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bertos/net/pocketcmd.c

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+/**
+ * \file
+ * <!--
+ * This file is part of BeRTOS.
+ *
+ * Bertos is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ *
+ * As a special exception, you may use this file as part of a free software
+ * library without restriction.  Specifically, if other files instantiate
+ * templates or use macros or inline functions from this file, or you compile
+ * this file and link it with other files to produce an executable, this
+ * file does not by itself cause the resulting executable to be covered by
+ * the GNU General Public License.  This exception does not however
+ * invalidate any other reasons why the executable file might be covered by
+ * the GNU General Public License.
+ *
+ * Copyright 2007 Develer S.r.l. (http://www.develer.com/)
+ * -->
+ *
+ * \brief pocketBus protocol Command layer implementation.
+ *
+ * This module implements command layer over pocketBus
+ * protocol.
+ * Payload packets received by pocketBus are first checked for
+ * address matching.
+ * If a packet is addressed to us we look for a suitable
+ * callback function to call.
+ *
+ * The received payload format is as follows:
+ * <pre>
+ * +----------------------------------------+
+ * |  CMD |            DATA                 |
+ * +----------------------------------------+
+ * |      |                                 |
+ * +  2B  +           0..N Byte             +
+ * </pre>
+ *
+ * The CMD ID used is the same supplied by the master when
+ * the command was sent.
+ *
+ * \author Francesco Sacchi <batt@develer.com>
+ */
+
+#include "pocketcmd.h"
+#include "pocketbus.h"
+
+#include "cfg/cfg_pocketbus.h"
+
+// Define logging setting (for cfg/log.h module).
+#define LOG_LEVEL         POCKETBUS_LOG_LEVEL
+#define LOG_VERBOSITY     POCKETBUS_LOG_FORMAT
+#include <cfg/log.h>
+#include <cfg/debug.h>
+#include <cfg/macros.h>
+#include <cfg/module.h>
+
+#include <drv/timer.h>
+
+#include <cpu/byteorder.h>
+#include <cpu/detect.h>
+
+#include <string.h>
+
+/**
+ * pocketBus Command poll function.
+ * Call it to read and process pocketBus commands.
+ */
+void pocketcmd_poll(struct PocketCmdCtx *ctx)
+{
+	PocketCmdMsg msg;
+	while (pocketcmd_recv(ctx, &msg))
+	{
+		/* Check for command callback */
+		pocketcmd_hook_t callback = ctx->search(msg.cmd);
+
+		/* Call it if exists */
+		if (callback)
+			callback(&msg);
+	}
+}
+
+
+
+/**
+ * pocketBus Command recv function.
+ * Call it to read and process pocketBus commands.
+ */
+bool pocketcmd_recv(struct PocketCmdCtx *ctx, PocketCmdMsg *recv_msg)
+{
+	PocketMsg msg;
+
+	/* Try to read a packet from pocketBus */
+	while (pocketbus_recv(ctx->bus_ctx, &msg))
+	{
+		/* Check address */
+		if (msg.addr == ctx->addr ||
+		    msg.addr == POCKETBUS_BROADCAST_ADDR)
+		{
+
+			#if CPU_AVR
+				const PocketCmdHdr *hdr = (const PocketCmdHdr *)msg.payload;
+			#else
+				#if !CPU_ARM
+					#warning Fix alignment problem..
+					/*
+					 * The code below make one memcopy, this the only way to
+					 * solve alignment problem on ARM. If you are use other
+					 * architecture you should find other way to optimize
+					 * this code.
+					 */
+				#endif
+				PocketCmdHdr hd;
+				memcpy(&hd, msg.payload, sizeof(PocketCmdHdr));
+				const PocketCmdHdr *hdr =  &hd;
+			#endif
+
+			pocketcmd_t cmd = be16_to_cpu(hdr->cmd);
+
+			/* We're no longer waiting for a reply (in case we were) */
+			if (cmd == ctx->waiting)
+				ctx->waiting = PKTCMD_NULL;
+
+			recv_msg->cmd_ctx = ctx;
+			recv_msg->cmd = cmd;
+			recv_msg->len = msg.len - sizeof(PocketCmdHdr);
+			recv_msg->buf = msg.payload + sizeof(PocketCmdHdr);
+
+			return true;
+		}
+	}
+
+	return false;
+}
+
+
+/**
+ * Send command \a cmd to/from slave adding \a len arguments in \a buf.
+ * Address used is contained in \a ctx->addr .
+ * If we are master and the message has a reply, you must set \a wait_reply to true.
+ * \return true if all is ok, false if we are already waiting a replay from another slave.
+ */
+bool pocketcmd_send(struct PocketCmdCtx *ctx, pocketcmd_t cmd, const void *buf, size_t len, bool wait_reply)
+{
+	/* Check if we are waiting a reply from someone */
+	if (ctx->waiting != PKTCMD_NULL)
+	{
+		/* Check is reply timeout is elapsed */
+		if (timer_clock() - ctx->reply_timer < ms_to_ticks(CONFIG_POCKETBUS_CMD_REPLY_TIMEOUT))
+		{
+			LOG_ERR("Pkt discard! waiting cmd[%04X]\n", ctx->waiting);
+			return false;
+		}
+		else
+		{
+			LOG_INFO("Timeout waiting cmd[%04X]\n", ctx->waiting);
+			ctx->waiting = PKTCMD_NULL;
+		}
+	}
+
+	/* Endianess! */
+	cmd = cpu_to_be16(cmd);
+
+	/* Send packet */
+	pocketbus_begin(ctx->bus_ctx, ctx->addr);
+	pocketbus_write(ctx->bus_ctx, &cmd, sizeof(cmd));
+	pocketbus_write(ctx->bus_ctx, buf, len);
+	pocketbus_end(ctx->bus_ctx);
+
+	if (wait_reply)
+	{
+		ctx->waiting = be16_to_cpu(cmd);
+		ctx->reply_timer = timer_clock();
+	}
+
+	return true;
+}
+
+/**
+ * Init pocketBus command layer.
+ * \a ctx is pocketBus command layer context.
+ * \a bus_ctx is pocketBus context.
+ * \a addr is slave address (see pocketcmd_setAddr for details.)
+ * \a search is the lookup function used to search command ID callbacks.
+ */
+void pocketcmd_init(struct PocketCmdCtx *ctx, struct PocketBusCtx *bus_ctx, pocketbus_addr_t addr, pocketcmd_lookup_t search)
+{
+	ASSERT(ctx);
+	ASSERT(bus_ctx);
+	ASSERT(search);
+	MOD_CHECK(timer);
+
+	memset(ctx, 0, sizeof(*ctx));
+	ctx->bus_ctx = bus_ctx;
+	ctx->search = search;
+	pocketcmd_setAddr(ctx, addr);
+}
+
+/**
+ * Helper function used to reply to master with an ACK.
+ */
+void pocketcmd_replyAck(struct PocketCmdMsg *msg)
+{
+	uint8_t ack[] = { POCKETBUS_ACK };
+
+	pocketcmd_slaveReply(msg->cmd_ctx, msg->cmd, ack, sizeof(ack));
+}
+
+/**
+ * Helper function used to reply to master with a NAK.
+ */
+void pocketcmd_replyNak(struct PocketCmdMsg *msg)
+{
+	uint8_t nak[] = { POCKETBUS_NAK };
+
+	pocketcmd_slaveReply(msg->cmd_ctx, msg->cmd, nak, sizeof(nak));
+}
+